Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 85542 — Peridot, AZ

ZIP code 85542 (Peridot, Gila County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is March 13 and the first fall frost November 19.

Where ZIP 85542 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone9a20 to 25 °F

Coldest night−6.7 to −3.9 °C

Last frostMar 13

First frostNov 19

2012 zone8b

Was 8b on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Peridot, AZ…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Peridot, AZ

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMarch 13median — 50% chance of a later frost

Safe for tender plantsApril 6only 10% chance of frost after

First fall frostNovember 19median — 10% chance by Nov 3

Growing season247 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 17 and returns around December 1.

From the NOAA station San Carlos Reservoir, AZ — 16 miles away, elevation 2,533 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 85542

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Jan 30 – Feb 13

SpinachSow outdoors · Jan 30 – Feb 20

Broccoli, cabbageStart indoors · Jan 2 – Jan 16

Broccoli, cabbageTransplant · Feb 20 – Mar 6

Onion setsPlant outdoors · Feb 13 – Feb 27

PotatoesPlant outdoors · Feb 20 – Mar 6

LettuceSow outdoors · Feb 13 – Feb 27

Carrots, beetsSow outdoors · Feb 20 – Mar 6

TomatoesStart indoors · Jan 16 – Jan 30

TomatoesTransplant · Mar 20 – Apr 3

Peppers, eggplantStart indoors · Jan 2 – Jan 16

Peppers, eggplantTransplant · Mar 27 – Apr 10

BeansSow outdoors · Mar 20 – Apr 3

Sweet cornSow outdoors · Mar 20 – Apr 3

Cucumbers, squashSow outdoors · Mar 20 – Apr 3

Fall lettuce, spinachSow outdoors · Sep 24 – Oct 8

GarlicPlant cloves · Nov 5 – Dec 10

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 13) and first fall frost (Nov 19) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 85542 came on Jan 30 — 3 days earlier than the 1991–2020 average (Feb 2).

average
Feb 22026
Jan 30

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 9a in Arizona

492 plants native to the lower 48 states, recorded in Arizona, and rated by the USDA to survive 20 °F or colder — the bottom of zone 9a. Each links to its USDA PLANTS profile.

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Peridot, AZ.

Soil in Peridot, AZ

The soil mapped at the center of ZIP 85542 is Argic Petrocalcids — very gravelly loam, well drained.

TextureVery gravelly loama good balance for most vegetables

pH7.6slightly alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1%low — add compost

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Argic Petrocalcids-Rock outcrop-Torriorthents complex, 2 to 60 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 85542; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Peridot, AZ

Summer high99 °Faverage high, July

Winter low31 °Faverage low, January

Hot days138days a year at 90 °F or more

Freezing nights42nights a year at 32 °F or less

Growing degree days5,890base 50 °F — the season’s usable heat

Longest day14 h 22 mindaylight on June 21

Shortest day9 h 57 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation13.4 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: San Carlos Reservoir, AZ (16 mi away); precipitation: San Carlos Reservoir, AZ (16 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

3 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

855308b

Bylas, AZ · 17 mi

855509a

San Carlos, AZ · 19 mi

855368b

Fort Thomas, AZ · 22 mi

Winkelman, AZ · 33 mi

Arizona planting zones →

Questions about 85542

What planting zone is ZIP code 85542?

ZIP code 85542 (Peridot, AZ) is in USDA hardiness zone 9a on the 2023 map: the coldest night of an average winter reaches 20 to 25 °F (−6.7 to −3.9 °C).

When is the last frost in Peridot, AZ?

The median last spring frost (32 °F) near 85542 is March 13; after April 6 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, San Carlos Reservoir station.

When is the first frost in Peridot, AZ?

The median first fall frost near 85542 is November 19, giving a median frost-free growing season of 247 days.

When should I plant tomatoes in 85542?

Start tomato seeds indoors around Jan 16 – Jan 30 and set transplants outside around Mar 20 – Apr 3, one to three weeks after the median last frost.

How much rain and snow does 85542 get?

About 13.4 inches of precipitation a year (NOAA 1991–2020 normals, San Carlos Reservoir station).

How hot do summers get in Peridot, AZ?

The average high peaks at 99 °F in July, with about 138 days a year at 90 °F or more.

What kind of soil does 85542 have?

The USDA soil survey maps Argic Petrocalcids at the center of ZIP 85542: very gravelly loam, well drained, pH about 7.6 (slightly alkaline).

Did spring come early in Peridot, AZ in 2026?

Spring leaf-out near 85542 came on Jan 30 in 2026, 3 days earlier than the 1991–2020 average (Feb 2), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Peridot, AZ?

Intermediate onions: the longest day near 85542 is 14 h 22 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 85542 change?

Yes. The 2012 USDA map put 85542 in zone 8b; the 2023 map puts it in zone 9a. The newer map uses 1991–2020 data and more weather stations.